| 1 | /* |
| 2 | * Copyright (c) 1997-1999 The Stanford SRP Authentication Project |
| 3 | * All Rights Reserved. |
| 4 | * |
| 5 | * Permission is hereby granted, free of charge, to any person obtaining |
| 6 | * a copy of this software and associated documentation files (the |
| 7 | * "Software"), to deal in the Software without restriction, including |
| 8 | * without limitation the rights to use, copy, modify, merge, publish, |
| 9 | * distribute, sublicense, and/or sell copies of the Software, and to |
| 10 | * permit persons to whom the Software is furnished to do so, subject to |
| 11 | * the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be |
| 14 | * included in all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, |
| 17 | * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY |
| 18 | * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. |
| 19 | * |
| 20 | * IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INCIDENTAL, |
| 21 | * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER |
| 22 | * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF |
| 23 | * THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT |
| 24 | * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 25 | * |
| 26 | * In addition, the following conditions apply: |
| 27 | * |
| 28 | * 1. Any software that incorporates the SRP authentication technology |
| 29 | * must display the following acknowlegment: |
| 30 | * "This product uses the 'Secure Remote Password' cryptographic |
| 31 | * authentication system developed by Tom Wu (tjw@CS.Stanford.EDU)." |
| 32 | * |
| 33 | * 2. Any software that incorporates all or part of the SRP distribution |
| 34 | * itself must also display the following acknowledgment: |
| 35 | * "This product includes software developed by Tom Wu and Eugene |
| 36 | * Jhong for the SRP Distribution (http://srp.stanford.edu/srp/)." |
| 37 | * |
| 38 | * 3. Redistributions in source or binary form must retain an intact copy |
| 39 | * of this copyright notice and list of conditions. |
| 40 | */ |
| 41 | |
| 42 | /*#define _POSIX_SOURCE*/ |
| 43 | #include <stdio.h> |
| 44 | #include "t_defines.h" |
| 45 | |
| 46 | static int |
| 47 | hexDigitToInt(c) |
| 48 | char c; |
| 49 | { |
| 50 | if(c >= '0' && c <= '9') |
| 51 | return c - '0'; |
| 52 | else if(c >= 'a' && c <= 'f') |
| 53 | return c - 'a' + 10; |
| 54 | else if(c >= 'A' && c <= 'F') |
| 55 | return c - 'A' + 10; |
| 56 | else |
| 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * Convert a hex string to a string of bytes; return size of dst |
| 62 | */ |
| 63 | _TYPE( int ) |
| 64 | t_fromhex(dst, src) |
| 65 | register char *dst, *src; |
| 66 | { |
| 67 | register char *chp = dst; |
| 68 | register unsigned size = strlen(src); |
| 69 | |
| 70 | /* FIXME: handle whitespace and non-hex digits by setting size and src |
| 71 | appropriately. */ |
| 72 | |
| 73 | if(size % 2 == 1) { |
| 74 | *chp++ = hexDigitToInt(*src++); |
| 75 | --size; |
| 76 | } |
| 77 | while(size > 0) { |
| 78 | *chp++ = (hexDigitToInt(*src) << 4) | hexDigitToInt(*(src + 1)); |
| 79 | src += 2; |
| 80 | size -= 2; |
| 81 | } |
| 82 | return chp - dst; |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * Convert a string of bytes to their hex representation |
| 87 | */ |
| 88 | _TYPE( char * ) |
| 89 | t_tohex(dst, src, size) |
| 90 | register char *dst, *src; |
| 91 | register unsigned size; |
| 92 | { |
| 93 | int notleading = 0; |
| 94 | |
| 95 | register char *chp = dst; |
| 96 | if (size != 0) do { |
| 97 | if(notleading || *src != '\0') { |
| 98 | notleading = 1; |
| 99 | sprintf(chp, "%.2x", * (unsigned char *) src); |
| 100 | chp += 2; |
| 101 | } |
| 102 | ++src; |
| 103 | } while (--size != 0); |
| 104 | return dst; |
| 105 | } |
| 106 | |
| 107 | static char b64table[] = |
| 108 | "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./"; |
| 109 | |
| 110 | /* |
| 111 | * Convert a base64 string into raw byte array representation. |
| 112 | */ |
| 113 | _TYPE( int ) |
| 114 | t_fromb64(dst, src) |
| 115 | register char *dst, *src; |
| 116 | { |
| 117 | unsigned char *a; |
| 118 | char *loc; |
| 119 | int i, j; |
| 120 | unsigned int size; |
| 121 | |
| 122 | while(*src && (*src == ' ' || *src == '\t' || *src == '\n')) |
| 123 | ++src; |
| 124 | size = strlen(src); |
| 125 | |
| 126 | a = malloc((size + 1) * sizeof(unsigned char)); |
| 127 | if(a == (unsigned char *) 0) |
| 128 | return -1; |
| 129 | |
| 130 | i = 0; |
| 131 | while(i < size) { |
| 132 | loc = strchr(b64table, src[i]); |
| 133 | if(loc == (char *) 0) |
| 134 | break; |
| 135 | else |
| 136 | a[i] = loc - b64table; |
| 137 | ++i; |
| 138 | } |
| 139 | size = i; |
| 140 | |
| 141 | i = size - 1; |
| 142 | j = size; |
| 143 | while(1) { |
| 144 | a[j] = a[i]; |
| 145 | if(--i < 0) |
| 146 | break; |
| 147 | a[j] |= (a[i] & 3) << 6; |
| 148 | --j; |
| 149 | a[j] = (unsigned char) ((a[i] & 0x3c) >> 2); |
| 150 | if(--i < 0) |
| 151 | break; |
| 152 | a[j] |= (a[i] & 0xf) << 4; |
| 153 | --j; |
| 154 | a[j] = (unsigned char) ((a[i] & 0x30) >> 4); |
| 155 | if(--i < 0) |
| 156 | break; |
| 157 | a[j] |= (a[i] << 2); |
| 158 | |
| 159 | a[--j] = 0; |
| 160 | if(--i < 0) |
| 161 | break; |
| 162 | } |
| 163 | |
| 164 | while(a[j] == 0 && j <= size) |
| 165 | ++j; |
| 166 | |
| 167 | memcpy(dst, a + j, size - j + 1); |
| 168 | free(a); |
| 169 | return size - j + 1; |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * Convert a raw byte string into a null-terminated base64 ASCII string. |
| 174 | */ |
| 175 | _TYPE( char * ) |
| 176 | t_tob64(dst, src, size) |
| 177 | register char *dst, *src; |
| 178 | register unsigned size; |
| 179 | { |
| 180 | int c, pos = size % 3; |
| 181 | unsigned char b0 = 0, b1 = 0, b2 = 0, notleading = 0; |
| 182 | char *olddst = dst; |
| 183 | |
| 184 | switch(pos) { |
| 185 | case 1: |
| 186 | b2 = src[0]; |
| 187 | break; |
| 188 | case 2: |
| 189 | b1 = src[0]; |
| 190 | b2 = src[1]; |
| 191 | break; |
| 192 | } |
| 193 | |
| 194 | while(1) { |
| 195 | c = (b0 & 0xfc) >> 2; |
| 196 | if(notleading || c != 0) { |
| 197 | *dst++ = b64table[c]; |
| 198 | notleading = 1; |
| 199 | } |
| 200 | c = ((b0 & 3) << 4) | ((b1 & 0xf0) >> 4); |
| 201 | if(notleading || c != 0) { |
| 202 | *dst++ = b64table[c]; |
| 203 | notleading = 1; |
| 204 | } |
| 205 | c = ((b1 & 0xf) << 2) | ((b2 & 0xc0) >> 6); |
| 206 | if(notleading || c != 0) { |
| 207 | *dst++ = b64table[c]; |
| 208 | notleading = 1; |
| 209 | } |
| 210 | c = b2 & 0x3f; |
| 211 | if(notleading || c != 0) { |
| 212 | *dst++ = b64table[c]; |
| 213 | notleading = 1; |
| 214 | } |
| 215 | if(pos >= size) |
| 216 | break; |
| 217 | else { |
| 218 | b0 = src[pos++]; |
| 219 | b1 = src[pos++]; |
| 220 | b2 = src[pos++]; |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | *dst++ = '\0'; |
| 225 | return olddst; |
| 226 | } |
| 227 | |